Among the projects we have planned for the coming year are the following: (1) Further elucidation of the role of ATP, external K ion, Na ion and Ca ions on the maintenance of the living state. (2) Continued investigations into the mechanism of K ion accumulation and Na ion exclusion in red and white erythrocyte ghosts. (3) The regulation of the resting potential of frog muscle cells by cardinal adsorbents (e.g., drugs, Ca ions, etc.) on the cell surface. (4) Continued investigation into the molecular mechanism underlying swelling, shrinkage and cell volume control.